&NA;The case of a 40‐year‐old man with syringobulbo‐myelia secondary to an unresectable spinal extramedullary tumor is described. Fifteen years previously, the patient had undergone a laminectomy of T8 through T12 for a “benign” spinal cord tumor at another hospital and had become paraplegic; the tumor (neurinoma) had been neglected for 12 years. Magnetic resonance imaging demonstrated a large thoracolumbar spinal tumor with syringobulbo‐myelia. Polysomnography showed central‐, peripheral‐, and mixed‐type sleep apneas. After the failure of an attempted syringoperitoneal shunt, cordectomy at the level of T6 was performed with a good result. The mechanisms of the formation of syringomyelia and sleep apnea secondary to a caudal spinal extramedullary tumor are discussed. (Neurosurgery24:118‐124, 1989)